Related papers: Inelastic Backaction due to Quantum Point Contact …
Small differential conductance oscillations as a function of source-drain bias were observed and systematically studied in an asymmetric quantum point contact (QPC). These oscillations become significantly suppressed in a small in-plane…
The coherent time evolution of electrons in double quantum dots induced by fast bias-voltage switches is studied theoretically. As it was shown experimentally, such driven double quantum dots are potential devices for controlled…
We show that the coherent mixing of different transverse modes, due to forward scattering of carriers by soft impurity- or boundary potentials leads to a nonlinear, asymmetric current response of quantum point contacts (QPC). The…
Under a strong quantum measurement, the motion of an oscillator is disturbed by the measurement back-action, as required by the Heisenberg uncertainty principle. When a mechanical oscillator is continuously monitored via an electromagnetic…
The influence of measurement back action on electro-optic sampling of electromagnetic quantum fluctuations is investigated. Based on a cascaded treatment of the nonlinear interaction between a near-infrared coherent probe and the…
We summarize the main results of a microscopically based kinetic theory, applicable to open quantum point contacts (QPCs) driven up to high fields. The governing role of gauge invariance -- and the many-body sum rules for the electron gas…
We discuss decoherence due to electromagnetic fluctuations in charge qubits formed by two lateral quantum dots. We use an effective circuit model to evaluate correlations of voltage fluctuations in the qubit setup. These correlations allows…
Quantum electro-mechanical systems offer a unique opportunity to probe quantum noise properties in macroscopic devices, properties which ultimately stem from the Heisenberg Uncertainty Principle. A simple example of this is expected to…
A fractional quasiparticle charge is a manifestation of strong interactions in the fractional quantum Hall effect. Nevertheless, shot noise of quasiparticles is well described by a formula, derived for noninteracting charges. We explain the…
Based on the scattering matrix theory and non-equilibrium green function method, we have investigated the fluctuations of charge and spin current of the systems which consists of a quantum dot (QD) with a resonant level coupled to two…
Electron charge transport through a quantum point contact (QPC) driven by an asymmetric spin bias is studied. A large charge current is induced when the transmission coefficient of the QPC jumps from one integer plateau to the next.…
We study the effects of quantum fluctuations on the transport properties of multiband superconductors near a pair-breaking quantum critical point. For this purpose, we consider a minimal model of the quantum phase transition in a system…
A non-equilibrium theory describing the charge qubit dynamics measured by a quantum point contact is developed based on Schwinger-Keldysh's approach. Using the real-time diagram technique, we derive the master equation to all orders in…
Double quantum dots are one of the promising two-state quantum systems for realizing qubits. In the quest of successfully manipulating and reading information in qubit systems, it is of prime interest to control the charge response of the…
We consider a mechanism of spin decay for an electron spin in a quantum dot due to coupling to a nearby quantum point contact (QPC) with and without an applied bias voltage. The coupling of spin to charge is induced by the spin-orbit…
The origin of non-classical correlations is difficult to identify since the uncertainty principle requires that information obtained about one observable invariably results in the disturbance of any other non-commuting observable. Here,…
Continuous quantum measurement and feedback induce energy exchange between a dissipative qubit and a monitor even in the steady state, as a measurement backaction. Using the Lindblad equation, we identified the maximum and minimum values of…
We study the quantum charge noise and measurement properties of the double Cooper pair resonance point in a superconducting single-electron transistor (SSET) coupled to a Josephson charge qubit. Using a density matrix approach for the…
We investigate charge qubit measurements using a single electron transistor, with focus on the backaction-induced renormalization of qubit parameters. It is revealed the renormalized dynamics leads to a number of intriguing features in the…
Solid-state systems which mimic two-level atoms are being actively developed. Improving the quantum coherence of these systems, for instance spin qubits or single photon emitters using semiconductor quantum dots, involves dealing with…